ALUMINA. 449 



ALUMINA. 



This body never occurs in the animal organism ; it has only 

 been found in certain fossil bones into which it has undoubtedly 

 entered by infiltration. Its absence in the animal organism is easily 

 explained; any alumina conveyed into the intestinal canal enters 

 into insoluble combination with organic substances, especially with 

 the constituents of the bile, which cannot be resorbed. 



After taking 3 grammes of basic sulphate of alumina within 

 the space of 48 hours, I was unable to find a trace of alumina in 

 the whole of the collected urine; it was, however, present in the 

 ash of the solid excrements. The excrements were entirely devoid 

 of odour for some days after I took this substance. 



ARSENIC. 



Devergie* and Orfilaf believed that they had found arsenic in 

 all animal bones, and hence that it should be regarded as an inte- 

 gral constituent of the animal organism. Subsequent investiga- 

 tions have, however, shown that there must have been some fallacy 

 in the method of analysis pursued by these chemists, and that this 

 view is altogether erroneous. 



When positive experiments seemed to show that arsenic existed 

 in the bones, chemists thought they had found an explanation of 

 the apparent fact in the circumstance that phosphorus and arsenic 

 are so frequently associated together; if the discovery of Walchner 

 and Schafhautl that the sediments of most chalybeate waters con- 

 tain arsenic had been then known, this would doubtless have been 

 regarded as strong additional proof of the presence of arsenic in the 

 animal organism. 



Arsenic acts in so noxious a manner on the animal organism, 

 even in the smallest doses (as we see from experiments on animals), 

 that nature actively eliminates this deleterious substance as rapidly 

 as possible from the body. 



MeurerJ has made experiments on horses (animals which, as 

 is well known, can bear large doses of arsenic), and von Bibra 

 on rabbits, from whence it appears that most of the arsenic is 



* Ann. d'Hygiene publ. Oct. 1839, p. 482. 



t Ibid. Juill. 1840, p. 163. 



+ Arch. d. Pharm. Bd. 26, S. 15. 



Untersuch. iiber die Knochen u. s. w. S. 112. 



2 G 



